Bounce Thread

import import import import import import import

java.awt.Container; java.awt.Dimension; java.awt.Graphics; java.awt.event.ActionEvent; java.awt.event.ActionListener; java.awt.event.WindowAdapter; java.awt.event.WindowEvent;

import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; public class BounceThread { public static void main(String[] args) { JFrame frame = new BounceThreadFrame(); frame.show(); } } class BounceThreadFrame extends JFrame { public BounceThreadFrame() { setSize(300, 200); setTitle("Bounce"); addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } }); Container contentPane = getContentPane(); canvas = new JPanel(); contentPane.add(canvas, "Center"); JPanel p = new JPanel(); addButton(p, "Start", new ActionListener() { public void actionPerformed(ActionEvent evt) { Ball b = new Ball(canvas); b.start(); } });

}

addButton(p, "Close", new ActionListener() { public void actionPerformed(ActionEvent evt) { canvas.setVisible(false); System.exit(0); } }); contentPane.add(p, "South");

public void addButton(Container c, String title, ActionListener a) { JButton b = new JButton(title); c.add(b); b.addActionListener(a); } private JPanel canvas; }

class Ball extends Thread { public Ball(JPanel b) { box = b; } public void draw() { Graphics g = box.getGraphics(); g.fillOval(x, y, XSIZE, YSIZE); g.dispose(); } public void move() { if (!box.isVisible()) return; Graphics g = box.getGraphics(); g.setXORMode(box.getBackground()); g.fillOval(x, y, XSIZE, YSIZE); x += dx; y += dy; Dimension d = box.getSize(); if (x < 0) { x = 0; dx = -dx; } if (x + XSIZE >= d.width) { x = d.width - XSIZE; dx = -dx; } if (y < 0) { y = 0; dy = -dy; } if (y + YSIZE >= d.height) { y = d.height - YSIZE; dy = -dy; } g.fillOval(x, y, XSIZE, YSIZE); g.dispose(); } public void run() { try { draw(); for (int i = 1; i <= 1000; i++) { move(); sleep(5); } } catch (InterruptedException e) { } } private JPanel box; private static final int XSIZE = 10; private static final int YSIZE = 10;

private int x = 0; private int y = 0; private int dx = 2; private int dy = 2; }